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Veterinarian: State should consider deer-feeding ban to combat CWD

October 15, 2012

Veterinarian: State should consider deer-feeding ban to combat CWD

UNIVERSITY PARK, Pa. -- On the heels of finding chronic wasting disease in a Pennsylvania deer, it's time for the state's game commissioners to consider a ban on deer feeding, according to a veterinarian in Penn State's College of Agricultural Sciences.

It actually is past time, noted David Wolfgang, extension veterinarian and field studies director in veterinary and biomedical sciences.

"The commissioners should follow the advice they have been given by a variety of deer experts, including the agency's own wildlife veterinarian, and stop the feeding of deer," he said. "When we feed deer, we congregate the animals, and that dramatically increases the potential that diseases, such as chronic wasting disease (CWD), will spread among them. There is no disagreement about that."

The Board of Game Commissioners in the past has outlawed the feeding of bears and elk in the state, so there is precedent for banning the feeding of deer, Wolfgang pointed out. "It would be wise for them to go ahead now and do the right thing for the wildlife of Pennsylvania," he said.

Wolfgang represents Penn State on the state's Chronic Wasting Disease Task Force, which also includes representatives from the Game Commission and the state departments of agriculture and health. He is most concerned about another practice that game commissioners could stop: the placing of salt or mineral blocks for deer.

"Where salt licks or mineral blocks are put out, obviously deer congregate, and that is bad enough," Wolfgang explained. "But what's worse is that after being exposed to rain and snow, the minerals leach into the surrounding ground, and then for years deer bite and chew at the dirt.

"If a CWD-infected deer would visit the mineral lick, prions that spread the disease likely would get into the soil from its urine and feces. The last thing we want is for deer to be eating dirt in areas where deer have congregated."

Wolfgang, who is a past president of the Pennsylvania Veterinary Medical Association, also is worried about the wide use of deer urine by bowhunters as a lure or attractant. He suggested that game commissioners consider banning that practice in Pennsylvania, as well.

Doe urine, collected at deer farms across the country, is packaged commercially and sold to help archers draw into arrow-shooting range the mature bucks they seek.

"Some scientists now wonder if the wide distribution of doe urine might be partly responsible for the spread of CWD from the West to the East," he said.

"Doe urine from deer in other states should not be introduced into Pennsylvania soils. Even the small risk that the purchased doe urine might contain CWD-causing prions should discourage responsible hunters from using it."

The Pennsylvania Department of Agriculture in early October confirmed the first positive case of chronic wasting disease in the state on a deer farm in Adams County. The 3-year-old doe was born at a deer farm in Lycoming County and had lived at a deer farm in York County as well. Subsequently the state quarantined all three locations.

Agriculture Department officials are now trying to determine whether other captive deer at those facilities were infected, and if CWD might have been passed onto wild deer in those areas.

The disease attacks the brains of infected deer, elk and moose, producing small lesions that eventually result in death. It is transmitted by direct animal-to-animal contact through saliva, feces and urine.

Infected animals may not show signs of the disease in the early stages, which can last for years. However, as the disease progresses, infected animals begin to lose body functions and display abnormal behaviors, such as staggering or failing to respond to threats, such as the approach of humans or predators. Animals may stand with legs spread far apart, carry their head and ears lowered, and often drool excessively.

Infected animals appear to be in poor body condition and some become emaciated. Infected animals are often found near water and drink large quantities. However, these symptoms are characteristic of diseases other than CWD and that is why the diagnosis comes only after death. The only certified test for CWD requires killing an animal and examining its brainstem.

CWD first was discovered in Colorado among captive mule deer in 1967 and since has been detected in 22 states and Canadian provinces, including Pennsylvania's neighboring states of New York, West Virginia and Maryland. Pennsylvania is the 23rd state to find CWD in either a captive or wild deer population and the 13th state to have it only in a captive deer herd.

Although chronic wasting disease is fatal in deer, elk and moose, there is no evidence that it can be transmitted to humans, according to the Centers for Disease Control and Prevention, and the World Health Organization.